Name: Innumeracy
Rating: 4.1 (33 reviews)
Author: John Allen Paulos

What’s in it for me? Lose your fear of numbers.

Mathematics can be quite a difficult subject, and anyone who struggled for years with sine functions, logarithms and probability distributions in school knows this all too well. Math is often seen as such a challenging discipline that many people, even the highly-educated, have developed a fear of it and shy away from anything involving numbers.

In our society, you can openly boast that mathematics was always your worst subject and that you’re not a “numbers person.” But people who fail to grasp the basic concepts of numbers and probability are innumerate – and innumeracy is not a minor issue.

In these blinks, you’ll learn how common innumeracy is and why it is a major risk. You’ll see how innumerate people struggle to handle many real-life situations and how a basic understanding of mathematical concepts can be of great benefit to you.

You’ll also learn

how many choices of outfit there are if you own five shirts and three pairs of pants;
why you should expect to spot a blond woman with a ponytail in a yellow car driven by a bearded, mustachioed black man in Los Angeles; and
why astrology is pseudoscience.

Innumerate people have trouble grasping basic mathematical principles and often fail to react appropriately to everyday events.

It’s rare to hear people openly admit to illiteracy; yet it’s quite common to hear someone acknowledge that math was his worst subject, or shrugging and saying that he’s simply not a numbers person.

But innumeracy – that is, lacking the basic notions of math – is nothing to boast about.

Being innumerate has a host of negative consequences, one of them being an inability to react appropriately and make accurate judgments in circumstances involving numbers and probability.

An incapacity to determine whether a figure in a given context is big or small makes innumerates prone to personalizing, when their numerical intuition is prejudiced by their own experience.

For instance, the probability of being eaten by an alligator is quite low, although it does sometimes happen. But an innumerate person might read a news story about such an event and develop an irrational fear of alligators, ignoring any statistical evidence demonstrating that gator attacks are a very rare occurrence.

Another negative effect of innumeracy is the inability to grasp the implications of simple mathematical principles.

Let’s take the multiplication principle, which holds that if we have m different ways of making a choice and n different ways of making a subsequent choice, then we have m x n different ways to make these choices in succession.

To apply this elementary concept to an everyday situation, we would be able to conclude that a woman with five shirts and three pairs of pants would have 15 (5 x 3) outfit choices for any given day.

Going even further, the multiplication principle would yield the conclusion that if the woman were planning her outfits for an entire week, she would have 15 choices the first day, 15 the next day, and so on, or a total of 15⁷ choices – that’s 170,859,375 options!

Innumerate people, however, might reject the truth of this number and believe that it’s ridiculous that a few shirts and pants could result in such an incomprehensibly large number.

Innumerate people tend to misunderstand the concept of coincidences, which are improbable, yet common, events.

In 1492, Christopher Columbus discovered the New World. In 1942, Enrico Fermi discovered the atom. Coincidence? Sigmund Freud might say, “I think not!” The famous founder of psychoanalysis claimed that there was no such thing as a coincidence.

But what is a coincidence in the first place? Coincidences are improbable events, but they actually happen quite often – so much so, in fact, that we should sometimes expect them to happen.

We face trade-offs on a regular basis, but mathematical understanding can help us approach decisions in daily life

Math isn’t just a world of numbers disconnected from our day-to-day lives; it can actually shed light on why people in society act as they do.

Consider the concept of trade-offs. When faced with decisions, we often have to make a trade-off between competing concerns, such as trying to determine whether your donation to one charity will be used more wisely by another. Mathematics can help us understand how we tend to approach these trade-offs.

Key ideas in Innumeracy